[clang] 155d2d5 - Revert "[Sema] Address-space sensitive check for unbounded arrays (v2)"
Chris Hamilton via cfe-commits
cfe-commits at lists.llvm.org
Tue Sep 29 13:46:25 PDT 2020
Author: Chris Hamilton
Date: 2020-09-29T22:46:14+02:00
New Revision: 155d2d5300551c6ac26eaeef259d73d62f939d0b
URL: https://github.com/llvm/llvm-project/commit/155d2d5300551c6ac26eaeef259d73d62f939d0b
DIFF: https://github.com/llvm/llvm-project/commit/155d2d5300551c6ac26eaeef259d73d62f939d0b.diff
LOG: Revert "[Sema] Address-space sensitive check for unbounded arrays (v2)"
This reverts commit d9ee935679e7164d1c47e351bbbcf5c25742b59c.
Added:
Modified:
clang/include/clang/Basic/DiagnosticSemaKinds.td
clang/lib/Sema/SemaChecking.cpp
clang/test/Sema/const-eval.c
clang/test/SemaCXX/constant-expression-cxx1y.cpp
Removed:
clang/test/Sema/unbounded-array-bounds.c
################################################################################
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 4562d1114694..f29eec316971 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -8915,14 +8915,6 @@ def warn_array_index_precedes_bounds : Warning<
def warn_array_index_exceeds_bounds : Warning<
"array index %0 is past the end of the array (which contains %1 "
"element%s2)">, InGroup<ArrayBounds>;
-def warn_ptr_arith_exceeds_max_addressable_bounds : Warning<
- "the pointer incremented by %0 refers past the last possible element for an array in %1-bit "
- "address space containing %2-bit (%3-byte) elements (max possible %4 element%s5)">,
- InGroup<ArrayBounds>;
-def warn_array_index_exceeds_max_addressable_bounds : Warning<
- "array index %0 refers past the last possible element for an array in %1-bit "
- "address space containing %2-bit (%3-byte) elements (max possible %4 element%s5)">,
- InGroup<ArrayBounds>;
def note_array_declared_here : Note<
"array %0 declared here">;
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index a5de6a5c88db..eeb322262400 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -14057,11 +14057,11 @@ void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
const ConstantArrayType *ArrayTy =
Context.getAsConstantArrayType(BaseExpr->getType());
- const Type *BaseType =
- ArrayTy == nullptr ? nullptr : ArrayTy->getElementType().getTypePtr();
- bool IsUnboundedArray = (BaseType == nullptr);
- if (EffectiveType->isDependentType() ||
- (!IsUnboundedArray && BaseType->isDependentType()))
+ if (!ArrayTy)
+ return;
+
+ const Type *BaseType = ArrayTy->getElementType().getTypePtr();
+ if (EffectiveType->isDependentType() || BaseType->isDependentType())
return;
Expr::EvalResult Result;
@@ -14069,10 +14069,8 @@ void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
return;
llvm::APSInt index = Result.Val.getInt();
- if (IndexNegated) {
- index.setIsUnsigned(false);
+ if (IndexNegated)
index = -index;
- }
const NamedDecl *ND = nullptr;
if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(BaseExpr))
@@ -14080,69 +14078,6 @@ void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
if (const MemberExpr *ME = dyn_cast<MemberExpr>(BaseExpr))
ND = ME->getMemberDecl();
- if (IsUnboundedArray) {
- if (index.isUnsigned() || !index.isNegative()) {
- const auto &ASTC = getASTContext();
- unsigned AddrBits =
- ASTC.getTargetInfo().getPointerWidth(ASTC.getTargetAddressSpace(
- EffectiveType->getCanonicalTypeInternal()));
- if (index.getBitWidth() < AddrBits)
- index = index.zext(AddrBits);
- CharUnits ElemCharUnits = ASTC.getTypeSizeInChars(EffectiveType);
- llvm::APInt ElemBytes(index.getBitWidth(), ElemCharUnits.getQuantity());
- // If index has more active bits than address space, we already know
- // we have a bounds violation to warn about. Otherwise, compute
- // address of (index + 1)th element, and warn about bounds violation
- // only if that address exceeds address space.
- if (index.getActiveBits() <= AddrBits) {
- bool Overflow;
- llvm::APInt Product(index);
- Product += 1;
- Product = Product.umul_ov(ElemBytes, Overflow);
- if (!Overflow && Product.getActiveBits() <= AddrBits)
- return;
- }
-
- // Need to compute max possible elements in address space, since that
- // is included in diag message.
- llvm::APInt MaxElems = llvm::APInt::getMaxValue(AddrBits);
- MaxElems = MaxElems.zext(std::max(AddrBits + 1, ElemBytes.getBitWidth()));
- MaxElems += 1;
- ElemBytes = ElemBytes.zextOrTrunc(MaxElems.getBitWidth());
- MaxElems = MaxElems.udiv(ElemBytes);
-
- unsigned DiagID =
- ASE ? diag::warn_array_index_exceeds_max_addressable_bounds
- : diag::warn_ptr_arith_exceeds_max_addressable_bounds;
-
- // Diag message shows element size in bits and in "bytes" (platform-
- // dependent CharUnits)
- DiagRuntimeBehavior(BaseExpr->getBeginLoc(), BaseExpr,
- PDiag(DiagID)
- << index.toString(10, true) << AddrBits
- << (unsigned)ASTC.toBits(ElemCharUnits)
- << ElemBytes.toString(10, false)
- << MaxElems.toString(10, false)
- << (unsigned)MaxElems.getLimitedValue(~0U)
- << IndexExpr->getSourceRange());
-
- if (!ND) {
- // Try harder to find a NamedDecl to point at in the note.
- while (const auto *ASE = dyn_cast<ArraySubscriptExpr>(BaseExpr))
- BaseExpr = ASE->getBase()->IgnoreParenCasts();
- if (const auto *DRE = dyn_cast<DeclRefExpr>(BaseExpr))
- ND = DRE->getDecl();
- if (const auto *ME = dyn_cast<MemberExpr>(BaseExpr))
- ND = ME->getMemberDecl();
- }
-
- if (ND)
- DiagRuntimeBehavior(ND->getBeginLoc(), BaseExpr,
- PDiag(diag::note_array_declared_here) << ND);
- }
- return;
- }
-
if (index.isUnsigned() || !index.isNegative()) {
// It is possible that the type of the base expression after
// IgnoreParenCasts is incomplete, even though the type of the base
@@ -14205,8 +14140,9 @@ void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
}
}
- unsigned DiagID = ASE ? diag::warn_array_index_exceeds_bounds
- : diag::warn_ptr_arith_exceeds_bounds;
+ unsigned DiagID = diag::warn_ptr_arith_exceeds_bounds;
+ if (ASE)
+ DiagID = diag::warn_array_index_exceeds_bounds;
DiagRuntimeBehavior(BaseExpr->getBeginLoc(), BaseExpr,
PDiag(DiagID) << index.toString(10, true)
@@ -14227,11 +14163,12 @@ void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
if (!ND) {
// Try harder to find a NamedDecl to point at in the note.
- while (const auto *ASE = dyn_cast<ArraySubscriptExpr>(BaseExpr))
+ while (const ArraySubscriptExpr *ASE =
+ dyn_cast<ArraySubscriptExpr>(BaseExpr))
BaseExpr = ASE->getBase()->IgnoreParenCasts();
- if (const auto *DRE = dyn_cast<DeclRefExpr>(BaseExpr))
+ if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(BaseExpr))
ND = DRE->getDecl();
- if (const auto *ME = dyn_cast<MemberExpr>(BaseExpr))
+ if (const MemberExpr *ME = dyn_cast<MemberExpr>(BaseExpr))
ND = ME->getMemberDecl();
}
diff --git a/clang/test/Sema/const-eval.c b/clang/test/Sema/const-eval.c
index c94539ab1de2..bbcbb0e25237 100644
--- a/clang/test/Sema/const-eval.c
+++ b/clang/test/Sema/const-eval.c
@@ -140,10 +140,10 @@ EVAL_EXPR(52, &pr24622 == (void *)&PR24622); // expected-error {{must have a con
// We evaluate these by providing 2s' complement semantics in constant
// expressions, like we do for integers.
-void *PR28739a = (__int128)(unsigned long)-1 + &PR28739a; // expected-warning {{the pointer incremented by 18446744073709551615 refers past the last possible element for an array in 64-bit address space containing 64-bit (8-byte) elements (max possible 2305843009213693952 elements)}}
-void *PR28739b = &PR28739b + (__int128)(unsigned long)-1; // expected-warning {{refers past the last possible element}}
-__int128 PR28739c = (&PR28739c + (__int128)(unsigned long)-1) - &PR28739c; // expected-warning {{refers past the last possible element}}
-void *PR28739d = &(&PR28739d)[(__int128)(unsigned long)-1]; // expected-warning {{refers past the last possible element}}
+void *PR28739a = (__int128)(unsigned long)-1 + &PR28739a;
+void *PR28739b = &PR28739b + (__int128)(unsigned long)-1;
+__int128 PR28739c = (&PR28739c + (__int128)(unsigned long)-1) - &PR28739c;
+void *PR28739d = &(&PR28739d)[(__int128)(unsigned long)-1];
struct PR35214_X {
int k;
diff --git a/clang/test/Sema/unbounded-array-bounds.c b/clang/test/Sema/unbounded-array-bounds.c
deleted file mode 100644
index d47463ff9434..000000000000
--- a/clang/test/Sema/unbounded-array-bounds.c
+++ /dev/null
@@ -1,80 +0,0 @@
-// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -fsyntax-only %s 2>&1 | FileCheck --check-prefix=CHECK-X86-ADDR64 %s \
-// RUN: --implicit-check-not 'past the last possible element'
-// RUN: %clang_cc1 -triple i386-pc-linux-gnu -fsyntax-only %s 2>&1 | FileCheck --check-prefix=CHECK-I386-ADDR32 %s \
-// RUN: --implicit-check-not 'past the last possible element'
-// RUN: %clang_cc1 -triple avr-pc-linux-gnu -fsyntax-only %s 2>&1 | FileCheck --check-prefix=CHECK-AVR-ADDR16 %s \
-// RUN: --implicit-check-not 'past the last possible element'
-
-struct S {
- long long a;
- char b;
- long long c;
- short d;
-};
-
-struct S s[];
-
-void f1() {
- ++s[3].a;
- ++s[7073650413200313099].b;
- // CHECK-X86-ADDR64: :[[@LINE-1]]:5: warning: array index 7073650413200313099 refers past the last possible element for an array in 64-bit address space containing 256-bit (32-byte) elements (max possible 576460752303423488 elements)
- // CHECK-I386-ADDR32: :[[@LINE-2]]:5: warning: {{.*}} past the last possible element {{.*}} in 32-bit {{.*}} (max possible 178956970 elements)
- // CHECK-AVR-ADDR16: :[[@LINE-3]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements)
- ++s[7073650].c;
- // CHECK-AVR-ADDR16: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements)
-}
-
-long long ll[];
-
-void f2() {
- ++ll[3];
- ++ll[2705843009213693952];
- // CHECK-X86-ADDR64: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 64-bit {{.*}} (max possible 2305843009213693952 elements)
- // CHECK-I386-ADDR32: :[[@LINE-2]]:5: warning: {{.*}} past the last possible element {{.*}} in 32-bit {{.*}} (max possible 536870912 elements)
- // CHECK-AVR-ADDR16: :[[@LINE-3]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 8192 elements)
- ++ll[847073650];
- // CHECK-I386-ADDR32: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 32-bit {{.*}} (max possible 536870912 elements)
- // CHECK-AVR-ADDR16: :[[@LINE-2]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 8192 elements)
-}
-
-void f3(struct S p[]) {
- ++p[3].a;
- ++p[7073650413200313099].b;
- // CHECK-X86-ADDR64: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 64-bit {{.*}} (max possible 576460752303423488 elements)
- // CHECK-I386-ADDR32: :[[@LINE-2]]:5: warning: {{.*}} past the last possible element {{.*}} in 32-bit {{.*}} (max possible 178956970 elements)
- // CHECK-AVR-ADDR16: :[[@LINE-3]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements)
- ++p[7073650].c;
- // CHECK-AVR-ADDR16: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements)
-}
-
-void f4(struct S *p) {
- p += 3;
- p += 7073650413200313099;
- // CHECK-X86-ADDR64: :[[@LINE-1]]:3: warning: the pointer incremented by 7073650413200313099 refers past the last possible element for an array in 64-bit address space containing 256-bit (32-byte) elements (max possible 576460752303423488 elements)
- // CHECK-I386-ADDR32: :[[@LINE-2]]:3: warning: {{.*}} past the last possible element {{.*}} in 32-bit {{.*}} (max possible 178956970 elements)
- // CHECK-AVR-ADDR16: :[[@LINE-3]]:3: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements)
- p += 7073650;
- // CHECK-AVR-ADDR16: :[[@LINE-1]]:3: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements)
-}
-
-struct BQ {
- struct S bigblock[3276];
-};
-
-struct BQ bq[];
-
-void f5() {
- ++bq[0].bigblock[0].a;
- ++bq[1].bigblock[0].a;
- // CHECK-AVR-ADDR16: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 1 element)
-}
-
-void f6() {
- int ints[] = {1, 3, 5, 7, 8, 6, 4, 5, 9};
- int const n_ints = sizeof(ints) / sizeof(int);
- unsigned long long const N = 3;
-
- int *middle = &ints[0] + n_ints / 2;
- // Should NOT produce a warning.
- *(middle + 5 - N) = 22;
-}
diff --git a/clang/test/SemaCXX/constant-expression-cxx1y.cpp b/clang/test/SemaCXX/constant-expression-cxx1y.cpp
index 7fe71d485350..8bc4f88a63a9 100644
--- a/clang/test/SemaCXX/constant-expression-cxx1y.cpp
+++ b/clang/test/SemaCXX/constant-expression-cxx1y.cpp
@@ -1018,9 +1018,8 @@ constexpr int S = sum(Cs); // expected-error{{must be initialized by a constant
}
constexpr void PR28739(int n) { // expected-error {{never produces a constant}}
- int *p = &n; // expected-note {{declared here}}
+ int *p = &n;
p += (__int128)(unsigned long)-1; // expected-note {{cannot refer to element 18446744073709551615 of non-array object in a constant expression}}
- // expected-warning at -1 {{the pointer incremented by 18446744073709551615 refers past the last possible element for an array in 64-bit address space containing 32-bit (4-byte) elements (max possible 4611686018427387904 elements)}}
}
constexpr void Void(int n) {
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